### Legal Retirement Age

The concept of a legal retirement age, often termed pensionable age, refers to the age at which an individual is eligible to start receiving full retirement benefits from the government or from a mandatory pension scheme. This age can vary significantly from country to country and may depend on factors such as the individual's date of birth, gender, type of employment, and changes in government policy. 

#### Historical Development of Retirement Age

The idea of establishing a retirement age began taking shape with the introduction of state pensions in the early 20th century. For example, Germany under Chancellor Otto von Bismarck was the first country to introduce an old-age social insurance program in 1889, setting the pension age at 70. Over the decades, many countries have set up their own versions of public pension systems, determining retirement ages based on the economic climate, life expectancy, and the financial sustainability of their pension systems.

#### Factors Influencing Retirement Age

The determination of retirement age is influenced by a variety of factors including:
- **Demographic changes**: Increases in life expectancy prompt adjustments in retirement ages to ensure the sustainability of pension systems.
- **Economic factors**: Economic pressures and workforce productivity can lead employers and governments to adjust the retirement age upward or downward.
- **Social considerations**: Quality of life, health standards, and public opinions also influence retirement policy decisions.
- **Labor market needs**: In some cases, shortages in skilled labor due to demographic shifts prompt an increase in retirement age, retaining older experienced workers longer.

#### International Trends in Retirement Age

In many countries, there has been a trend towards increasing the retirement age, prompted largely by increased life expectancy and aging populations, which strain public pension systems. For instance:
- In the United States, the full retirement age for social security has been gradually increasing. For those born in 1960 or later, the full retirement age is 67.
- Many European countries have been following this trend as well, with France planning to gradually increase its retirement age to 64 by 2030.
- Similarly, Australia has planned increases in the retirement age to 67 by 2023.

#### Legal Retirement Age for Those Born Post-1960

For individuals born after 1960, the legal retirement age has been set at 67 in several countries, reflecting adjustments made to cope with demographic changes. This adjustment is primarily aimed at ensuring the financial viability of pension systems and reflects broader global trends towards later retirement. Here’s how it works:
- **Eligibility for Benefits**: At 67, individuals become eligible to receive their full pension benefits without any reductions which would apply if they had opted for early retirement.
- **Policy Rationale**: This policy helps in balancing the pension systems as it spreads out the payouts over a longer period, considering that people are living longer and healthier lives.
- **Impact on the Economy**: Delaying the retirement age helps sustain the labor force longer, potentially increasing economic productivity and stability.

#### Conclusion

The setting of the retirement age to 67 for those born post-1960 represents a significant policy measure designed to address the challenges of modern demographic trends and economic needs. As countries worldwide grapple with similar challenges, it is likely that the analyses and adjustments of retirement ages will continue to be a key feature of social policy debates.